1. Field
The invention is related to apparatuses, systems and methods for characterization of optical fibers included in multi-fiber array cables and patch-cords. More specifically, the invention relates to a system and method for finding fiber polarity, fiber sequencing, and the type of multi-fiber optical cables and patch-cords.
2. Related Art and Background
Optical fiber networks, such as Enterprise, and data centers are using multi-fiber array cables. A multi-fiber array cable may include a multitude of optical fibers arranged in various configurations. Installers of multi-fiber array cables and network owners have a need to characterize, test and trouble-shoot the cables and individual fibers. Examples of some of the tests used to characterize the fibers are: tests for finding the power loss along specific fibers in the cables, tests for finding the length of the various fibers in the cables, tests for finding the reflectance of fiber's ends, tests for finding the polarity of the fibers in the cables and tests for finding fiber sequencing in a multi-fiber array cable.
The Optical Time Domain Reflectometer (OTDR) is one of the most useful tools for characterization and testing of fiber optic cables. The OTDR can be used to measure the length of individual fibers in a cable, fiber attenuation, reflectivity of fiber ends, splice loss, connection losses. The OTDR can also be used to find fiber faults for each individual fiber in a cable. Patent Application Pub. No. US 2008/0297773 A1 describes using sets of OTDR receive-fibers with different lengths of marker events to verify optical fiber connectivity.
Users need a means of connecting to the array cable to make the required measurements and identify the fiber sequencing for each fiber in the cable. It is important to minimize multiple connections to the fiber to reduce contamination or damage due to repeated matings. Sometimes, multi-fiber cables are miss-mapped or mis-sequenced. That means that a certain cable has a different fiber sequence than the sequence it is supposed to have and the technician may not be aware of such mis-mapping or mis-sequencing. Using mis-mapped or mis-sequenced cables in a network may result in malfunction of the network.
Current solutions to the problems described above require a fan-out or cassette to be able to access individual fibers with optical test equipment. These solutions do not provide a means of identifying or verifying the fiber sequencing. Test personnel could test each fiber without knowing the mapping. These could result in problems during turn-up of the system if the fibers do not properly align with the rest of the system and equipment.
It is an object of the invention to provide an apparatus, a system and a method that enables a single OTDR technician to determine fiber polarity and fiber sequencing in a multi-fiber array cable. Consequently the technician will be able to determine the type of cable tested (e.g. type A, B, C, and others).